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Novel extracellular hyper acidophil and thermostable α‐amylase from Micrococcus sp.NS 211

Samie, Nima, Reddy, Padma R. M., Ashouri, Masoumeh
DieStärke = 2012 v.64 no.2 pp. 136-144
EDTA (chelating agent), Micrococcus, bacteria, calcium chloride, chromatography, detergents, enzyme activity, genes, laundry, magnesium chloride, molecular weight, pH, sodium chloride, sodium citrate, starch, temperature, thermal stability, urea
Among several bacteria examined in this study, a hyper acidophil and thermostable Micrococcus sp.NS 211 designated as M.Amy NS 211 was selected for production of amylase using starch agar plates with following incubation at 85°C. Identification by 16SrRNA on selected bacterium disclosed the highest similarity for protean regions of this gene, 27 F and 1492R as Micrococcus sp.NS 211. Although activity of M.Amy NS 211 was established at temperatures between 70 and 110°C and pH ranges 1.2–8.0, the optimum temperature and pH was achieved at 85°C and 3.5 in sodium citrate buffer system respectively. Two‐step chromatography was performed using (CM Bio‐Gel A) and (Bio‐Gel A‐150) columns to purify 84 kDa hyper acidophil and thermostable α‐amylase. SDS‐PAGE analysis showed molecular mass and amylolytic activity as single band. Enhancement of enzyme activity was obtained in presence of 5 mM MnCl2 (298%), CaCl2 (347%), FeCl2 (211%), MgCl2 (253%), ZnCl2 (146%), NiCl (142%), NaCl (141%), Na‐sulfate (153%) while inhibition was observed with (5 mM) EDTA, PMSF (3 mM), urea (8 M), and SDS (1%) at 143, 134, 43, and 119%, respectively. M.Amy NS 211 can be applied in laundry detergents, textile, and modern relevant industrial processes at extreme temperatures and under acidic conditions.